usr/src/sys/kern/init_main.c

/*
 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)init_main.c 7.43 (Berkeley) %G%
 */

#include "param.h"
#include "filedesc.h"
#include "kernel.h"
#include "mount.h"
#include "map.h"
#include "proc.h"
#include "resourcevar.h"
#include "signalvar.h"
#include "systm.h"
#include "vnode.h"
#include "conf.h"
#include "buf.h"
#include "clist.h"
#include "malloc.h"
#include "protosw.h"
#include "reboot.h"
#include "user.h"


#include "machine/cpu.h"

#include "vm/vm.h"

char    copyright[] =
"Copyright (c) 1982,1986,1989,1991 The Regents of the University of California.\nAll rights reserved.\n\n";

/*
 * Components of process 0;
 * never freed.
 */
struct  session session0;
struct  pgrp pgrp0;
struct  proc proc0;
struct  pcred cred0;
struct  filedesc0 filedesc0;
struct  plimit limit0;
struct  vmspace vmspace0;
struct  proc *curproc = &proc0;
struct  proc *initproc, *pageproc;

int     cmask = CMASK;
extern  struct user *proc0paddr;
extern  int (*mountroot)();

struct  vnode *rootvp, *swapdev_vp;
int     boothowto;

/*
 * System startup; initialize the world, create process 0,
 * mount root filesystem, and fork to create init and pagedaemon.
 * Most of the hard work is done in the lower-level initialization
 * routines including startup(), which does memory initialization
 * and autoconfiguration.
 */
main()
{
        register int i;
        register struct proc *p;
        register struct filedesc0 *fdp;
        int s, rval[2];

        /*
         * Initialize curproc before any possible traps/probes
         * to simplify trap processing.
         */
        p = &proc0;
        curproc = p;
        /*
         * Attempt to find console and initialize
         * in case of early panic or other messages.
         */
        consinit();
        printf(copyright);

        vm_mem_init();
        kmeminit();
        cpu_startup();

        /*
         * set up system process 0 (swapper)
         */
        p = &proc0;
        curproc = p;

        allproc = p;
        p->p_prev = &allproc;
        p->p_pgrp = &pgrp0;
        pgrphash[0] = &pgrp0;
        pgrp0.pg_mem = p;
        pgrp0.pg_session = &session0;
        session0.s_count = 1;
        session0.s_leader = p;

        p->p_flag = SLOAD|SSYS;
        p->p_stat = SRUN;
        p->p_nice = NZERO;
        bcopy("swapper", p->p_comm, sizeof ("swapper"));

        /*
         * Setup credentials
         */
        cred0.p_refcnt = 1;
        p->p_cred = &cred0;
        p->p_ucred = crget();
        p->p_ucred->cr_ngroups = 1;     /* group 0 */

        /*
         * Create the file descriptor table for process 0.
         */
        fdp = &filedesc0;
        p->p_fd = &fdp->fd_fd;
        fdp->fd_fd.fd_refcnt = 1;
        fdp->fd_fd.fd_cmask = cmask;
        fdp->fd_fd.fd_ofiles = fdp->fd_dfiles;
        fdp->fd_fd.fd_ofileflags = fdp->fd_dfileflags;
        fdp->fd_fd.fd_nfiles = NDFILE;

        /*
         * Set initial limits
         */
        p->p_limit = &limit0;
        for (i = 0; i < sizeof(p->p_rlimit)/sizeof(p->p_rlimit[0]); i++)
                limit0.pl_rlimit[i].rlim_cur =
                    limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
        limit0.pl_rlimit[RLIMIT_OFILE].rlim_cur = NOFILE;
        limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur = MAXUPRC;
        limit0.p_refcnt = 1;

        /*
         * Allocate a prototype map so we have something to fork
         */
        p->p_vmspace = &vmspace0;
        vmspace0.vm_refcnt = 1;
        pmap_pinit(&vmspace0.vm_pmap);
        vm_map_init(&p->p_vmspace->vm_map, round_page(VM_MIN_ADDRESS),
            trunc_page(VM_MAX_ADDRESS), TRUE);
        vmspace0.vm_map.pmap = &vmspace0.vm_pmap;
        p->p_addr = proc0paddr;                         /* XXX */

        /*
         * We continue to place resource usage info
         * and signal actions in the user struct so they're pageable.
         */
        p->p_stats = &p->p_addr->u_stats;
        p->p_sigacts = &p->p_addr->u_sigacts;

        rqinit();

        /*
         * configure virtual memory system,
         * set vm rlimits
         */
        vm_init_limits(p);

        /*
         * Initialize the file systems.
         *
         * Get vnodes for swapdev and rootdev.
         */
        vfsinit();
        if (bdevvp(swapdev, &swapdev_vp) || bdevvp(rootdev, &rootvp))
                panic("can't setup bdevvp's");

        startrtclock();
#if defined(vax)
#include "kg.h"
#if NKG > 0
        startkgclock();
#endif
#endif

        /*
         * Initialize tables, protocols, and set up well-known inodes.
         */
        mbinit();
        cinit();
#ifdef SYSVSHM
        shminit();
#endif
#include "sl.h"
#if NSL > 0
        slattach();                     /* XXX */
#endif
#include "loop.h"
#if NLOOP > 0
        loattach();                     /* XXX */
#endif
        /*
         * Block reception of incoming packets
         * until protocols have been initialized.
         */
        s = splimp();
        ifinit();
        domaininit();
        splx(s);

#ifdef GPROF
        kmstartup();
#endif

        /* kick off timeout driven events by calling first time */
        roundrobin();
        schedcpu();
        enablertclock();                /* enable realtime clock interrupts */

        /*
         * Set up the root file system and vnode.
         */
        if ((*mountroot)())
                panic("cannot mount root");
        /*
         * Get vnode for '/'.
         * Setup rootdir and fdp->fd_fd.fd_cdir to point to it.
         */
        if (VFS_ROOT(rootfs, &rootdir))
                panic("cannot find root vnode");
        fdp->fd_fd.fd_cdir = rootdir;
        VREF(fdp->fd_fd.fd_cdir);
        VOP_UNLOCK(rootdir);
        fdp->fd_fd.fd_rdir = NULL;
        swapinit();

        /*
         * Now can look at time, having had a chance
         * to verify the time from the file system.
         */
        boottime = p->p_stats->p_start = time;

        /*
         * make init process
         */
        siginit(p);
        if (fork(p, (void *) NULL, rval))
                panic("fork init");
        if (rval[1]) {
                static char initflags[] = "-sf";
                char *ip = initflags + 1;
                vm_offset_t addr = 0;
                extern int icode[];             /* user init code */
                extern int szicode;             /* size of icode */

                /*
                 * Now in process 1.  Set init flags into icode,
                 * get a minimal address space, copy out "icode",
                 * and return to it to do an exec of init.
                 */
                p = curproc;
                initproc = p;
                if (boothowto&RB_SINGLE)
                        *ip++ = 's';
#ifdef notyet
                if (boothowto&RB_FASTBOOT)
                        *ip++ = 'f';
#endif
                *ip++ = '\0';

                if (vm_allocate(&p->p_vmspace->vm_map, &addr,
                    round_page(szicode + sizeof(initflags)), FALSE) != 0 ||
                    addr != 0)
                        panic("init: couldn't allocate at zero");

                /* need just enough stack to exec from */
                addr = trunc_page(USRSTACK - PAGE_SIZE);
                if (vm_allocate(&p->p_vmspace->vm_map, &addr,
                    PAGE_SIZE, FALSE) != KERN_SUCCESS)
                        panic("vm_allocate init stack");
                p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
                (void) copyout((caddr_t)icode, (caddr_t)0, (unsigned)szicode);
                (void) copyout(initflags, (caddr_t)szicode, sizeof(initflags));
                return;                 /* returns to icode */
        }

        /*
         * Start up pageout daemon (process 2).
         */
        if (fork(p, (void *) NULL, rval))
                panic("fork pager");
        if (rval[1]) {
                /*
                 * Now in process 2.
                 */
                p = curproc;
                pageproc = p;
                p->p_flag |= SLOAD|SSYS;                /* XXX */
                bcopy("pagedaemon", curproc->p_comm, sizeof ("pagedaemon"));
                vm_pageout();
                /*NOTREACHED*/
        }

        /*
         * enter scheduling loop
         */
        sched();
}